Dye record medium, record disc producing apparatus, and information recording/reproducing apparatus

ABSTRACT

A dye record disc has a disc shape substrate having a track-forming surface divided into a read-only area and a recordable area. A reproducing track is formed on the track-forming surface in the read-only area, and has a plurality of pits, each of the pits comprising a dye material, and having a shape corresponding to the reproducing information. A recording/reproducing track is formed on the track-forming surface in the recordable area, and extends continuously, the recording/reproducing track comprising the same dye material as each of the pits. The information reproducing apparatus includes an initial light emitting device for emitting an initial light beam to all of the pits before reproduction, in order to change reflectance of all of the pits; a reproducing light emitting device for emitting a reproducing light to each of the pits; a receiving device for receiving reflected light of the reproducing light reflected by the reproducing track, and generating a receiving signal corresponding to the received reflective light; and a reproducing device for reproducing the reproducing information on the basis of the receiving signal.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 09/071,493,filed May 4, 1998 now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a hybrid disc of a dye membranerecording type having a read-only area and a recordable area.

2. Description of the Related Art

A read-only optical disc, such as a CD (Compact Disc) of a read onlytype has become widespread. Such a read-only optical disc has phase pitsto record information. Each phase pit is formed such that its depth isequal to one-four wavelength λ of a light beam used for reproduction,i.e., λ/4.

On the other hand, a recordable optical disc is developed. Especially,as one type of the recordable optical disc, a write once type opticaldisc, such as a CD-R (CD-Recordable) and the like is frequentlydeveloped. Such a write once type optical disc has a recording layercomposed of a dye membrane. When information is recorded on the writeonce type optical disc, a light beam modulated such that its intensityis changed depending on the information is emitted onto the recordinglayer. Thereby, reflectance of the dye membrane at the irradiated partis changed. Thus, the information is recorded on the disc. Whenreproducing, the recorded information is reproduced on the basis of achange of reflectance.

Here, in the above mentioned write once type optical disc, the intensityof the light beam used for recording is alternatively changed between afirst intensity and a second intensity. Namely, when the information tobe recorded onto the disc is a high level, the intensity of the lightbeam is the first intensity. When the information is a low level, theintensity of the light beam is the second intensity. The secondintensity is weaker than the first intensity, and the second intensityis roughly or accurately equal to the intensity of a light beam used forreproduction. When the information is recorded on the disc, reflectanceof the dye membrane is changed by switching over the intensity of thelight beam between the first intensity and the second intensity. Inorder to increase the intensity of the light beam, it is preferable thatthe light beam is efficiently used.

Furthermore, when the information is recorded on the write one typeoptical disc, it is necessary that the light beam is accurately emittedon the target track in order to record the information on it accurately.Therefore, a tracking control is performed. Various kinds of methods toperform the tracking control have been developed. In view of theefficiency of the light beam, a push-pull method is preferably used asthe tracking control for recording information on the write once typeoptical disc. In the push-pull method, a single light beam is used forboth recording and the tracking control. In case that the trackingcontrol is performed by using the push-pull method, in order to increasea level of a tracking error signal to the maximum, it is necessary thatheight (depth) of the information track of the write once type opticaldisc is one-eight waveform λ of the light beam, i.e., λ/8.

Therefore, in the write once type optical disc, in view of bothrecording and reproduction, a predetermined value between λ/8 to λ/4 isset as the depth of the information track.

Here, in view of the recent development of multimedia, an optical dischaving the function of the read-only optical disc and the function ofthe write once type optical disc is desired.

However, it is difficult to realize such an optical disc (Hereinafter,it is referred to as a “hybrid disc”.). The reason is that the depth ofthe phase pit of the read-only optical disc is different from that ofthe information track of the write once type optical disc. Namely, thedepth of the phase pit of the read-only optical disc is λ/4, but thedepth of the information track of the write once type optical disc isthe predetermined value between λ/8 to λ/4 (not λ/4). It is verydifficult in view of a yield to form the phase pit and the informationtrack each having different depth on a single disc.

SUMMARY OF THE INVENTION

It is therefore a first object of the present invention to provide ahybrid type dye record medium which can be easily produced.

Furthermore, it is a second object of the present invention to provide arecord disc producing apparatus which can easily produce a record disc,such as a hybrid type dye record medium.

Moreover, it is a third object of the present invention to provide aninformation reproducing apparatus which can surely reproduce informationrecorded on a hybrid type dye record medium.

According to the present invention, the above mentioned first object canbe achieved by a dye record medium provide with: a substrate having atrack-forming-surface divided into a read-only area and a recordablearea; a reproducing track formed on the track-forming-surface in theread-only area, and constructed by an arrangement of a plurality ofpits, each of the pits comprising a dye material, having a shapecorresponding to reproducing information, and having a constantpredetermined height; and a recording/reproducing track formed on thetrack-forming-surface in the recordable area, and extendingcontinuously, the recording/reproducing track comprising the same dyematerial as each of the pits, and having the same predetermined heightas each of the pits.

Namely, the dye record medium has a two areas, i.e., the read-only areaand the recordable area. In the read-only area, reproduction informationis recorded on the track-forming-surface in advance as the reproducingtrack constructed by the arrangement of the plurality of pits. In theread-only area, reproducing the reproducing information is possible, butrecording a new information is impossible. On the other hand, in therecordable area, both recording new information and reproducing therecorded information are possible.

In the read-only area, the reproducing track is formed. The reproducingtrack is constructed by the arrangement of the plurality of the pits.Each pit has a shape corresponding to the reproducing information.Namely, the shape of each pit is changed depending on conditions of thereproducing information. Thereby, when the reproducing track isirradiated with the light beam, reflectance of the light beam is changedon the basis of the shape of each pit. Furthermore, each pit is composedof at least dye material. Moreover, each pit having a constantpredetermined height. The height means a length between thetrack-forming-surface and the top of the pit.

In the recordable area, the recording/reproducing track is formed.Unlike the reproducing track, the recording/reproducing trackcontinuously extends. Namely, as the recording/reproducing track doesnot have pits, there is no break or gap in the recording/reproducingtrack.

Furthermore, the recording/reproducing track is compose of at least thesame dye material as each of the pits of the reproducing track.Moreover, the recording/reproducing track has the same predeterminedheight as each of the pits of the reproducing track.

Accordingly, when the dye record medium is produced, the reproducingtrack and the recording/reproducing track can be simultaneously producedin the same process. As a result, it is possible to simplify theproduction process of the dye record medium and to produce the dyerecord medium easy.

Moreover, since the reproducing track is constructed by the arrangementof the plurality of pits each having the shape corresponding to thereproducing information, it is possible to reproduce the reproducinginformation surely.

Furthermore, the top surface of each of the pits and the top surface ofthe recording/reproducing track may be in the same plane. Accordingly,when the dye record medium is produced, the reproducing track and therecording/reproducing track can be simultaneously produced in the sameprocess. As a result, it is possible to produce the hybrid type dyerecord medium easy.

Moreover, the substrate of the dye record medium has: a base; areflective layer formed on the base, for reflecting the light beam; anda dye membrane formed on the reflective layer, a surface of the dyemembrane is the track-forming-surface, each of the pits is integratedwith the dye membrane, and the recording/reproducing track is integratedwith the dye membrane.

Thus, when the dye record medium is produced, each of the pits and therecording/reproducing track can be simultaneously produced in the sameprocess. Accordingly, it is possible to produce the hybrid type dyerecord medium easy.

According to the present invention, the above mentioned second objectcan be achieved by a record disc producing apparatus for producing arecord disc, the record disc having: a disc shape substrate having atrack-forming-surface divided into a read-only area and a recordablearea; a reproducing track formed on the track-forming-surface in theread-only area, and constructed by an arrangement of a plurality ofpits, each of the pits having a shape corresponding to reproducinginformation; and a recording/reproducing track formed on thetrack-forming-surface in the recordable area, and extendingcontinuously, the record disc producing apparatus having: a rotationdevice for rotating the record disc; a sending device for sending therecord disc in a radial direction of the recording disc; and an emittingdevice for emitting a first light beam having an intensity modulated onthe basis of reproducing information when the reproducing track isformed in the read-only area, emitting a second light beam having aconstant intensity when the recording/reproducing track is formed in therecordable area, and controlling the intensity of the first light beamand the intensity of the second intensity such that both the reproducingtrack and the recording/reproducing track have the same height.

Namely, the rotation device rotates the record disc, while the sendingdevice sends the record disc in the radial direction of the record disc.The emitting device emits the light beam to the record disc, while theseoperation is performed. The emitting device emits the first light beamhaving an intensity modulated on the basis of reproducing information,when the reproducing track is formed in the read-only area. On the otherhand, the emitting device emits the second light beam having a constantintensity when the recording/reproducing track is formed in therecordable area. Furthermore, the emitting device controls the intensityof the first light beam and the intensity of the second intensity suchthat both the reproducing track and the recording/reproducing track havethe same height. Thus, the reproducing track and therecording/reproducing track can be easily formed, and the height of thereproduce track and the height of the recording/reproducing track can beeasily equalized with each other.

According to the present invention, the above mentioned third object canbe achieved by an information reproducing apparatus for reproducinginformation recorded on a dye record disc, the dye record disccomprising: a disc shape substrate having a track-forming-surfacedivided into a read-only area and a recordable area; a reproducing trackformed on the track-forming-surface in the read-only area, andconstructed by an arrangement of a plurality of pits, each of the pitscomprising a dye material, and having a shape corresponding to thereproducing information; and a recording/reproducing track formed on thetrack-forming-surface in the recordable area, and extendingcontinuously, the recording/reproducing track comprising the same dyematerial as each of the pits, the information reproducing apparatushaving: an initial light emitting device for emitting an initial lightbeam to all of the pits before reproduction, in order to changereflectance of all of the pits; a reproducing light emitting device foremitting a reproducing light to each of the pits; a receiving device forreceiving a reflective light of the reproducing light reflected by thereproducing track, and generating a receiving signal corresponding tothe received reflective light; and a reproducing device for reproducingthe reproducing information on the basis of the receiving signal.

Namely, before the information reproducing apparatus actually reproducesthe reproducing information recorded in the read-only area, the initiallight emitting device emits the initial light beam to all of the pits.Thereby, reflectance of all of the pits are changed. This enables toreproduce the reproducing information.

Thereafter, the reproducing light emitting device emits the reproducinglight to each of the pits, and the receiving device receives thereflective light of the reproducing light reflected by the reproducingtrack. Furthermore, the receiving device generates a receiving signalcorresponding to the received reflective light. Next, the reproducingdevice reproduces the reproducing information on the basis of thereceiving signal.

Accordingly, it is possible to detect the reproducing information fromthe dye pits accurately, and to reproduce the reproducing informationsurely.

According to the present invention, the above mentioned third object canbe also achieved by an information recording/reproducing apparatus forrecording information onto a dye record disc and reproducing informationrecorded on the dye record disc, the dye record disc having: a discshape substrate having a track-forming-surface divided into a read-onlyarea and a recordable area; a reproducing track formed on thetrack-forming-surface in the read-only area, and constructed by anarrangement of a plurality of pits, each of the pits including a dyematerial, and having a shape corresponding to the reproducinginformation; and a recording/reproducing track formed on thetrack-forming-surface in the recordable area, and extendingcontinuously, the recording/reproducing track including the same dyematerial as each of the pits, the information recording/reproducingapparatus having: an initial light emitting device for emitting aninitial light beam to all of the pits before reproduction, in order tochange reflectance of all of the pits; a reproducing light emittingdevice for emitting a reproducing light to each of the pits; a receivingdevice for receiving a reflective light of the reproducing lightreflected by the reproducing track, and generating a receiving signalcorresponding to the received reflective light; a reproducing device forreproducing the reproducing information on the basis of the receivingsignal; and a recording light emitting device for emitting a recordinglight modulated on the basis of the recording information onto therecording/reproducing track, in order to record the record informationonto the recording/reproducing track by changing reflectance of therecording/reproducing track.

Thus, the recording information is recorded by changing reflectance ofthe recording/reproducing track. Accordingly, the reproducinginformation recorded in the read-only area and information recorded onthe recording/reproducing track in the recordable area can be reproducedrespectively, by using the same reproducing light beam.

Furthermore, the initial light emitting device emits the initial lightbeam having an intensity not more than an intensity of the recordinglight and more than an intensity of the reproducing light. Thereby, therecording light emitting device, the reproducing light emitting device,and the initial light emitting device can be united, and it is possibleto simplify the configuration of the apparatus.

According to the present invention, the above mentioned third object canbe also achieved by an information reproducing method of reproducinginformation recorded on a dye record disc, the dye record disc having: adisc shape substrate having a track-forming-surface divided into aread-only area and a recordable area; a reproducing track formed on thetrack-forming-surface in the read-only area, and constructed by anarrangement of a plurality of pits, each of the pits including a dyematerial, and having a shape corresponding to the reproducinginformation; and a recording/reproducing track formed on thetrack-forming-surface in the recordable area, and extendingcontinuously, the recording/reproducing track including the same dyematerial as each of the pits, the information reproducing method havingthe processes of: emitting an initial light beam to all of the pitsbefore reproduction, in order to change reflectance of all of the pits;emitting a reproducing light to each of the pits; receiving a reflectivelight of the reproducing light reflected by the reproducing track, andgenerating a receiving signal corresponding to the received reflectivelight; and reproducing the reproducing information on the basis of thereceiving signal.

Namely, before the information reproducing apparatus actually reproducesthe reproducing information recorded in the read-only area, all of thepits are irradiated with the initial light. Thereby, reflectance of allof the pits are changed. This enables to reproduce the reproducinginformation.

Thereafter, each of the pits are irradiated with the reproducing light,and the reflective light of the reproducing light reflected by thereproducing track is received. Furthermore, the receiving signalcorresponding to the received reflective light is generated. Next, thereproducing information on the basis of the receiving signal isreproduced.

Accordingly, it is possible to detect the reproducing information fromthe dye pits accurately, and to reproduce the reproducing informationsurely.

The nature, utility, and further features of this invention will be moreclearly apparent from the following detailed description with respect topreferred embodiments of the invention when lead-in conjunction with theaccompanying drawings briefly described below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a hybrid disc of an embodiment of thepresent invention;

FIG. 2 is an enlarged sectional view showing a recordable area of thehybrid disc of the embodiment;

FIG. 3 is a diagram showing a record format in the recordable area ofthe embodiment;

FIG. 4 is an enlarged sectional view showing a ROM area of the hybriddisc of the embodiment;

FIG. 5 is a block diagram showing a cutting apparatus of an embodimentof the present invention;

FIG. 6 is a block diagram showing an information recording/reproducingapparatus of an embodiment of the present invention; and

FIG. 7 is a flowchart showing an operation of the informationrecording/reproducing apparatus of the embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the accompanying drawings, embodiments of the presentinvention will be now explained.

(I) Hybrid Disc

At first, an embodiment of the present invention with respect to a dyerecord medium will be explained with reference to FIGS. 1 to 4. A hybriddisc explained below is an embodiment of the present invention withrespect to a dye record medium. The hybrid disc has a read-only area (itis referred to as a “ROM area”.) and a recordable area. In the ROM area,only reproduction of information is possible. On the other hand, in therecordable area, both reproduction of information and only oncerecording of information are possible.

Here, a configuration of the hybrid disc is explained in further detail.FIG. 1 shows the whole configuration of the hybrid disc.

In FIG. 1, a hybrid disc 1 has: a clamp hole 101 for fixing the hybriddisc 1 on a disc mount; a lead-in area 102; a ROM area 103; a recordablearea 104; and a lead-out area 105. In each of the lead-in area 102 andthe lead-out area 105, information to be used for automaticallyreproducing information recorded on the hybrid disc 1 is recorded. Forexample, in the lead-in area 102, TOC (Table Of Contents) information isrecorded. The TOC information represents a type of disc, and is used fordistinction between the hybrid disc 1, an ordinary CD, a CD-ROM, or thelike. Furthermore, the total memory capacity of the ROM area 103 and therecordable area 104 is approximately equal to that of a standard typeDVD (about 5 G byte). Moreover, no information is recorded in an areabetween the clamp hole 101 and the lead-in area 102.

Next, a configuration of the recordable area 104 is explained withreference to FIG. 2. FIG. 2 shows the recordable area 104 in enlarged.

As shown in FIG. 2, in the recordable area 104, a dye membrane 5 isformed, and the recordable area 104 functions as a dye record mediumcapable of recording information only once. Furthermore, in therecordable area 104, a groove track 2 and a land track 3 are formed onthe surface 5A of the dye membrane 5. As shown in FIG. 2, the groovetrack 2 and the land track 3 are integrated with the dye membrane 5. Thegroove track 2 functions as a recording/reproducing track. The landtrack 3 guides a light beam B. For example, the light beam B is a laserbeam, and the light beam B is used for both recording and reproduction.Moreover, in the recordable area 104, a protection layer 7 and a goldvapor deposition surface 6 are formed. The protection layer 7 protectsthe groove track 2 and the land track 3. The a gold vapor depositionsurface 6 reflects the light beam B when information is reproduced. Apre-pit 4 is formed on the land track 3. The pre-pit 4 corresponds to apre-information. The pre-pit 4 is formed in advance. Namely, the pre-pit4 is formed at the stage that the hybrid disc 1 itself is produced.Moreover, for example, the height of the groove track 2 is approximately0.17 [μm].

Here, the pre-information recorded by forming the pre-pit 4 includesrotation control information and address information. The rotationcontrol information is used for controlling a rotation of the hybriddisc 1 when recording or reproducing. The address information indicatesa position in the recordable area 104.

Furthermore, in the recordable area 104, the rotation controlinformation is recorded by wobbling the groove track 2 depending onfrequency corresponding to rotation velocity of the hybrid disc 1. Likepre-pit 4, the wobbles are formed at the stage that the hybrid disc 1itself is produced. Namely, the rotation control information is recordedin advance.

When record information (Hereinafter, the recording information meansactual information to record, such as image information, documentinformation, music information, and so on, other than thepre-information.) is recorded in the recordable area 104, an informationrecording/reproducing apparatus described below detects the wobblingfrequency from the groove track 2, fetches the rotation controlinformation from the wobbling frequency, and rotates the hybrid disc 1in a predetermined rotation velocity on the basis of the rotationcontrol information. Furthermore, the information recording/reproducingapparatus detects the pre-pit 4, fetches the pre-information from thepre-pit 4, and sets an optimum power of the light beam B on the basis ofthe pre-information. Moreover, the information recording/reproducingapparatus extracts the address information from the pre-information,records the record information at a certain position in the recordablearea 104 on the basis of the address information.

Here, the record information is recorded by forming a record informationpit corresponding to the record information on the groove track 2. Therecord information pit is formed by irradiation of the light beam B.When the record information pit is formed, the light beam B is emittedonto the groove track 2 such that the center of the light beam B is justpositioned at the center of the groove track 2. At this time, as shownin FIG. 2, the diameter of the light spot SP is larger than the width ofthe groove track 2. Thereby, the light beam B is emitted both onto thegroove track 2 and the land track 3. A reflective light reflected by theland track 3 is used for detecting the pre-pit 4 and fetching thepre-information. The detection of the pre-pit 4 is performed by using apush-pull method. A photodetector divided by a parting line parallel toa rotation direction of the hybrid disc 1 is used in the push-pullmethod (Hereinafter, this method is referred to as a “radial push-pullmethod”.). A reflective light reflected by the groove track 2 is usedfor detecting the wobbling frequency. A clock signal to be used for therotation control is generated on the basis of the detected wobblingfrequency.

Next, a record format of the pre-information and the record informationin the recordable area 104 is explained with reference to FIG. 3. FIG. 3shows the record format. In FIG. 3, a diagram drawn at the upper partshows the record format of the record information, and a diagram drawnat the lower part shows a condition of the wobbles of the groove track2. The upward arrows arranged between the diagram showing the recordformat and the diagram showing the wobbles show positions of thepre-pits 4. In addition, the wobbles shown in FIG. 3 are exaggerated.The amplitude of the actual wobbles is smaller than that shown in FIG.3. Furthermore, the recording information is recorded on the center lineof the groove track 2 (shown by dotted line in FIG. 3).

As shown in FIG. 3, the record information is divide by sync-frame. Arecording sector is constructed by 26 sync-frames. An ECC (ErrorCorrecting Code) block is constructed by 16 recording sectors. Inaddition, each sync-frame has 1488 times unit length. The unit lengthcorresponds to the bit interval defined by the recording format.Hereinafter, the alphabet “T” represents the unit length. So, as shownin FIG. 3, the length of each sync-frame is 1488T. Moreover, synchronousinformation is recorded at the top part of each sync-frame. The lengthof the synchronous information is 14T. The synchronous information isused for synchronizing for each sync-frame.

In each sync-frame, one pre-pit 4 is formed at the position adjacent tothe part where the synchronous information is recorded. A synchronoussignal is generated on the basis of this pre-pit 4. Moreover, one or twopre-pits 4 are further formed in the area adjacent to the front part ofthe sync-frame. The address information is fetched from these pre-pits4. In addition, these pre-pits 4 used for fetching the addressinformation is not always formed. In the embodiment, in each recordingsector, the pre-pits 4 are formed in only either one of the evensync-frame and the odd sync-frame. For example, in FIG. 3, the pre-pits4 are formed in the even sync-frame, but they are not formed in the oddsync-frame.

The groove track 2 is wobbled in the constant wobbling frequency f0, forexample, 140 [kHz], with respect to the all sync-frame (8 waves arefitted in every one of the sync-frames.). The informationrecording/reproducing apparatus detects the constant wobbling frequencyf0, and generates a signal to control rotation of a spindle motor.

Next, a configuration of the ROM area 103 is explained with reference toFIG. 4. FIG. 4 shows the ROM area 103 in enlarged.

As shown in FIG. 4, like the recordable area 104, a land track 203 and agroove track 202 are formed in the ROM area 103. The land track 203 andthe groove track 202 are formed by the same dye membrane 5 as the groovetrack 2 and the land track 3 of the recordable area 102. Namely, theland track 203 and the groove track 202 are formed on the surface 5A ofthe dye membrane 5, and they are integrated with the dye membrane 5. Theheight of the groove track 202 is the same as that of the groove track 2(e.g., approximately 0.17 [μm]).

Furthermore, the groove track 202 is constructed by an arrangement of aplurality of dye pits P. Like a phase pit of a CD, the shape of each dyepit P corresponds to information to be recorded in the ROM area 103.Namely, the length of each dye pit P is changed between 3T to 14T,depending on the information to be recorded in the ROM area 103. Thus,in the ROM area 103, information is recorded by the arrangement of thedye pits P. In thickness of the dye membrane 5, the part between twophase pits P adjacently arranged along the groove track 202 is thinnerthan other parts of the grooving track 202 (the parts where the dye pitsP are formed). Moreover, the part between two phase pits P, the landtrack 203, and the land track 3 of the recordable area 102 (the partwhere the pre-pit 4 is not formed) are in the same plane.

When the information recorded by the arrangement of the dye pits P isreproduced, the light beam B is emitted as shown in FIG. 4. At thistime, the quantity of the reflective light of the light beam B isdifferent between the part where the dye pit is formed and the partwhere the dye pit is not formed. The information is reproduced bydetecting the difference. More concretely, in the embodiment, before theinformation is reproduced from the ROM area 103, the light beam B isemitted onto the all dye pits P in the recording power. Thereby, acharacteristic (e.g., reflectance) of the dye pits P (i.e., the dyemembrane 5 of the dye pits P) is changed. As a result, the reflectanceof the part where the dye pit P is formed becomes different from thereflectance of the part where the dye pit P is not formed. Thereafter,the information is reproduced on the basis of the reflective light ofthe light beam B. In addition, the recording power means the power ofthe light beam B when the record information pit is formed on the groovetrack 2 in the recordable area 104.

In addition, in the groove track 202 shown in FIG. 2, as it isunnecessary to fetch the rotation control information, the synchronousinformation, etc., a wobble and a pre-pit are not formed.

(II) Cutting Apparatus

Next, an embodiment of the present invention with respect to a recorddisc producing apparatus will be explained with reference to FIG. 5. Acutting apparatus explained below is an embodiment of the presentinvention with respect to a record disc producing apparatus. The cuttingapparatus is used for forming the ROM area 103 and the recordable area104 shown in FIGS. 2 and 4.

FIG. 5 shows a cutting apparatus 300. Referring to the FIG. 5, aconfiguration of the cutting apparatus 300 is explained. In addition,the cutting apparatus 300 is used for producing a stamper disc 400 inorder to mass-produce the hybrid disc 1.

As shown in FIG. 5, The cutting apparatus 300 has: data generators 10and 20; an 8-16 modulator 11; a parallel/serial converters 12 and 21; apre-format encoder 22; a clock signal generator 23, a laser generator24; a light converter 25; an objective lens 26; a spindle motor 29; arotation detector 30; a rotation servo circuit 31; a sending unit 32; aposition detector 33; and a servo circuit 34. Furthermore, the lasergenerator 24 has: a first emitter 24G for emitting a light beam L1 toform the groove tracks 2 and 202; and a second emitter 24L for emittinga light beam L2 to form the land tracks 3 and 203.

On the other hand, the stamper disc 400 has: a glass substrate 27serving as a base; and a resist 28 that is coated on the glass substrate27. The resist 28 is used for forming tracks.

Next, an operation to form the ROM area 103 is explained. When thecutting apparatus 300 forms the ROM area 103 on the stamper disc 400,the cutting apparatus 300 forms pits corresponding to information to berecorded into the ROM area 103. These pits are models of the dye pits Pof the hybrid disc 1. In this time, the data generator 10 generates datainformation Spr corresponding to the information to be recorded into theROM area 103. Next, the 8-16 modulator 11 modulates the data informationSpr on the basis of a clock signal CLK outputted from the clock signalgenerator 23. The frequency of the clock signal CLK corresponds to “T”.Furthermore, the 8-16 modulator 11 forms an ECC block with respect tothe data information Spr. Next, the parallel/serial converter 12parallel/serial-converts the data information Spr, and outputs recordinginformation Srr to the light converter 25.

Next, the light converter 25 modulates intensity of the light beam L1 onthe basis of the recording information Srr, and emits the light beam L1to the objective lens 26. At this time, the recording information Srr isconstructed by a combination of an “H” signal and an “L” signalcorresponding to the data information Spr. Furthermore, for example, the“H” signal corresponds to the weak intensity of the light beam L1, andthe “L” signal corresponds to the strong intensity of the light beam L1.Then, the light beam L1 modulated in this manner is emitted on theresist 28, and the pits corresponding to the dye pits P are formed onthe resist 28.

On the other hand, when the land track 203 is formed on the stamper disc400, the light beam L2 is emitted to the objective lens 26. Theintensity of the light beam L2 is kept constant by the DC (DirectCurrent) driving device (not shown in the drawings).

The light beam L1 having the modulated intensity and the light beam L2having the constant intensity are simultaneously emitted on the resist28 from the objective lens 26. Thus, the groove track 202 and the landtrack 203 are formed in the ROM area 103 on the resist 28.

The spindle motor 29 rotates the stamper disc 400, while the light beamL1 and the light beam L2 are emitted. The rotation detector 30 detectsthe rotation number of the stamper disc 400. The rotation servo circuit31 servo-controls the rotation of the stamper disc 400 on the basis ofthe detected rotation number. At this time, the rotation servo circuit31 outputs the rotation detecting signal Ss to the pre-format encoder 22and the spindle motor 29, each time the stamper disc 400 is rotated onerotation.

Moreover, while these operation are carried out, the sending unit 32 ismoved together with the spindle motor 29 and the stamper disc 400 in theradial direction of the stamper disc 400 in order to form the groovetrack 202 and the land track 203 in a spiral shape. At this time, theposition detector 33 detects a position of the sending unit 32, and thesending servo circuit 34 servo-controls the movement of the sending unit32 on the basis of the detected position of the sending unit 32.

Thus, the light beams L1 and L2 are emitted on the stamper disc 400,while the stamper disc 400 is rotated and moved in the radial direction.Thereby, the groove track 202 and the land track 203 are formed in thecoaxial spiral shape in the area corresponding to the ROM area 103 onthe stamper disc 400.

Next, an operation to form the recordable area 104 is explained. Whenthe cutting apparatus 300 forms the recordable area 104 on the stamperdisc 400, the cutting apparatus 300 forms pits corresponding to thepre-information, together with the land track 3. In this time, the datagenerator 20 generates data pre-information Spp corresponding to thepre-information. Next, the parallel/serial converter 21parallel/serial-converts the data pre-information Spp. Next, thepre-format encoder 22 further converts the data pre-information Spp intothe recording pre-information Sr on the basis of the clock signal CLKand the rotation detecting signal Ss, and outputs the recordingpre-information Sr to the light converter 25.

Next, the light converter 25 modulates intensity of the light beam L2 onthe basis of the recording pre-information Sr, and emits the light beamL2 to the objective lens 26. At this time, the record pre-information Sris constructed by a combination of an “H” signal and an “L” signalcorresponding to the data pre-information Spp. Furthermore, for example,the “H” signal corresponds to the weak intensity of the light beam L2,and the “L” signal corresponds to the strong intensity of the light beamL2. Then, the light beam L2 modulated in this manner is emitted on theresist 28, and the land track 3 having the pit corresponding to thepre-pit 4 is formed on the resist 28.

On the other hand, when the groove track 2 is formed on the stamper disc400, the light beam L1 is emitted to the objective lens 26. Theintensity of the light beam L1 is kept constant by the DC (DirectCurrent) driving device (not shown in the drawings). Furthermore, atthis time, the irradiate position is controlled in order to form thewobbles of the groove track 2 as shown in FIGS. 2 and 3.

The light beam L2 having the modulated intensity and the light beam L1having the constant intensity are simultaneously emitted on the resist28 from the objective lens 26. Thus, the groove track 2, the land track3 and the pits corresponding to the pre-pits 4 are formed in therecordable area 104 on the resist 28.

At this time, like forming the ROM area 103 on the stamper disc 400, thespindle motor 29, the rotation detector 30, the rotation servo circuit31, the sending unit 32, the position detector 33 and the sending servocircuit 34 operate.

Thus, the light beams L1 and L2 are emitted on the stamper disc 400,while the stamper disc 400 is rotated and moved in the radial direction.Thereby, the groove track 2 and the land track 3 are formed in thecoaxial spiral shape in the area corresponding to the recordable area104 on the stamper disc 400.

Here, the intensity of the light beam L2 when the ROM area 103 isformed, the intensity of the light beam L1 corresponding to the “H”signal when the ROM area 103 is formed, and the intensity of the lightbeam L2 corresponding to the “H” signal when the recordable area 104 isformed are the same intensity. Further, the intensity of the light beamL1 corresponding to the “L” signal when the ROM area 103 is formed, theintensity of the light beam L1 when the recordable area 104 is formed,and the intensity of the light beam L2 corresponding to the “L” signalwhen the recordable area 104 is formed are the same intensity.Accordingly, on the stamper disc 400, the part of the land track 3 wherethe pits corresponding to the pre-pits 4 are not formed, the land track203, the part of the groove track 202 where the pits corresponding tothe dye pits P are not formed are in the same plane. Further, the partof the land track 3 where the pits corresponding to the pre-pits 4 areformed, the groove track 2, and the part of the groove track 202 wherethe pits corresponding to the dye pits P are formed are in the sameplane.

After the cutting apparatus 300 produces the stamper disc 400, thehybrid disc 1 having the same shape as the stamper disc 400 ismass-produced. Namely, the resist 28 exposed by the light beams L1 andL2 is developed, and the developed resist 28 is treated by a conductiveprocess and a nickel electroforming process. Thereby, a nickel stamperdisc is produced. Next, the hybrid disc 1 is produced by using thenickel stamper disc. A 2P processing method or an injection moldingmethod is used for producing the hybrid disc 1.

In addition, in the produced hybrid disc 1, the part of the land track 3where the pre-pits 4 are not formed, the land track 203, and the part ofthe groove track 202 where the dye pits P are not formed are in the sameplane, and the part of the land track 3 where the pre-pits 4 are formed,the groove track 2 and the part of the groove track 202 where the dyepits P are formed are in the same plane.

(III) Information Recording/Reproducing Apparatus

Next, an embodiment of the present invention with respect to aninformation recording/reproducing apparatus is explained with referenceto FIGS. 6 and 7. An information recording/reproducing apparatusexplained below is an embodiment of the present invention. Theinformation recording/reproducing apparatus records the recordinginformation onto the hybrid disc 1, and reproduces information recordedon the hybrid disc 1. When recording the recording information into therecordable area 104, the information recording/reproducing apparatusdetects the pre-pits 4, fetches the address information on the basis ofthe pre-pits 4, determined the recording position on the basis of theaddress information, and records the recording information at thedetermined position. Furthermore, the information recording/reproducingapparatus detects the wobbles of the groove track 2 as a wobblingsignal, generates a base clock signal on the basis of the wobblingsignal, and controls the rotation of the hybrid disc 1 on the basis ofthe base clock signal.

Here, FIG. 6 shows a configuration of the informationrecording/reproducing apparatus 500. In FIG. 6, the apparatus 500 has: apickup 40 serving as an initial light beam emitter, a reproducing lightbeam emitter, a photo-receiver and a recording light beam emitter; areproducing amplifier 41 serving as a reproducing device; a decoder 42serving as the reproducing device; a pre-pit signal decoder 43; aspindle motor 44; a servo circuit 45; a processor 46; an encoder 47; aswitch 48; a power control circuit 49; and a laser drive circuit 50.

The pickup 40 has a laser diode, a polarization beam splitter, anobjective lens and a photodetector. The pickup 40 emits the light beam Bonto the dye membrane of the hybrid disc 1 on the basis of a laserdriving signal Sdl, detects the pre-pits 4 on the basis of a reflectivelight of the light beam B, and records the recording information in therecordable area 104. Furthermore, the pickup 40 reproduces reproducinginformation recorded in the ROM area 103 on the basis of the reflectivelight of the light beam B.

The reproducing amplifier 41 amplifies a detection signal outputted fromthe pickup 40. The detection signal Sdt includes informationcorresponding to the pre-pits 4 or the reproducing information.Furthermore, the reproducing amplifier 41 outputs a pre-pit signal Spptcorresponding to the pre-pits 4, or an amplified signal Sp correspondingto the reproducing information.

The decoder 42 performs an 8-16 demodulation and deinterleave in orderto decode the amplified signal Sp, and outputs a demodulated signal Sdmand a servo demodulation signal Ssd.

The pre-pit signal decoder 43 decodes the pre-pit signal Sppt, andoutputs a demodulated pre-pit signal Spd.

The servo circuit 45 outputs a pickup servo signal Ssp on the basis ofthe demodulated pre-pit signal Spd and servo demodulation signal Ssd, inorder to perform a focus servo control and a tracking servo control inthe pickup 40. Furthermore, the servo circuit 45 also outputs a spindleservo signal Sss on the basis of the demodulated pre-pit signal Spd andservo demodulation signal Ssd, in order to control the rotation of thespindle motor 44. The spindle motor 44 rotates the hybrid disc 1.

The processor 46 temporarily stores the recording information Srsinputted from the external, and outputs a recording information signalSr corresponding to the recording information Srs. Furthermore, theprocessor 46 outputs a reproducing signal Sot corresponding to thereproducing information to the external on the basis of the demodulatedsignal Sdm. Moreover, the processor 46 outputs a switching signal Ssw onthe basis of the demodulated pre-pit signal Spd.

Further, when the hybrid disc 1 is mounted onto a disc mount of theapparatus 500, the processor 46 outputs a control signal Srd to thepower control circuit 49 in order to emit the light beam B having aconstant intensity and the recording power onto the hybrid disc 1.

The encoder 47 adds an ECC code to the recording information signal Sr,and forms the ECC block. Furthermore, the encoder 47 performs aninterleave and an 8-16 modulation in order to process the ECC block, andoutputs the modulated signal Sre.

The switch 48 switches over a modulated signal Sre outputted from theencoder 47 and a constant voltage, and outputs either one of themodulated signal Sre and the constant voltage, as an output signal Spc.

The power control circuit 49 outputs a driving signal Sd on the basis ofthe output signal Spc and the control signal Srd, in order to control anoutput of the laser diode installed in the pickup 40.

The laser drive circuit 50 outputs the laser driving signal Sdl on thebasis of the driving signal Sd, in order to drive the laser diode and toemit the light beam B.

Next, a recording and a reproducing operation of the apparatus 500 isexplained with reference to FIG. 7.

When the apparatus 500 records the information onto the hybrid disc 1 orreproduce the information from the hybrid disc 1, at first, the pickup40 emits the light beam B to the lead-in area 102 of the hybrid disc 1,and read out the TOC information on the basis of the reflective light ofthe light beam B (Step 1). In addition, like detection of the pre-pits4, the radial push-pull method is used for reading out the TOCinformation.

Next, the processor 46 determines whether or not the disc mounted on thedisc mount is the hybrid disc 1 on the basis of the TOC information(Step 2). If the mounted disc 1 is a read-only disc, such as an ordinaryCD and a CD-ROM (Step 2; NO), the processor 46 next determines whetheror not an instruction to start the reproduction is inputted from theexternal (Step 3). If the instruction is not inputted (Step 3; NO), theprocessor 46 waits until the instruction is inputted. On the other hand,if the instruction is inputted (Step 3; YES), the switch 48 connects theconstant voltage to the power control circuit 49 on the basis of theswitching signal Ssw outputted from the processor 46. Namely, when theapparatus 500 reproduces the read-only disc, the constant voltage issupplied to the power control circuit 49, and the power control circuit49 sets the output power of the light beam B at the constantreproduction power that is lower than the recording power, on the basisof the constant voltage. More concretely, when the output signal Spccorresponding to the constant voltage is outputted to the power controlcircuit 49, the power control circuit 49 generates the driving signal Sdon the basis of the output signal Spc, and next, the laser drive circuit50 generates the laser driving signal Sdl on the basis of the drivingsignal Sd. Then, the driving signal Sd drives the laser diode installedin the pickup 40, and the pickup 40 emits the light beam B on theread-only disc. Thereby, information recorded on the read-only disc isdetected, and the demodulated signal Sdm corresponding to the detectedinformation is inputted onto the processor 46. Then, the processor 46outputs the reproduction signal Sot to the external (Step 8).

On the other hand, in the step 2, if the processor 46 determines thatthe disc mounted on the disc mount is the hybrid disc 1 (Step 2; YES),the pickup 40 is moved to the starting position in the ROM area 103(Step 4). Here, in the embodiment, the starting position is the mostinner circumferential portion in the ROM area 103. Next, the powercontrol circuit 49 outputs the control signal Sd on the basis of thecontrol signal Srd outputted from the processor 46. Thereby, the pickup40 emits the light beam B having the recording power. The light beam Bhaving the recording power is emitted onto the whole ROM area 103 (Step5). As a result, the character (reflectance) of the dye membrane (dyepits) formed in the ROM area 103 is changed, and this enables toreproduce the information recorded in the ROM area 103.

Next, the processor 46 determines whether or not the light beam B havingthe recording power is emitted onto the whole ROM area 103 (Step 6), Ifthe light beam B is not emitted onto the whole ROM area 103 (Step 6;NO), the irradiation is continued. On the other hand, if the light beamB is perfectly emitted onto the whole ROM area 103 (Step 6; YES), theprocessor 46 determines whether or not the recording information isrecorded (Step 7). If the recording information is recorded on therecordable area 104 (Step 7; YES), the switch 48 connects the encoder 47and the power control circuit 49 on the basis of the switching signalSsw, and the modulated signal Sre is supplied to the power controlcircuit 49 as the output signal Spc. Thereby, the power control circuit49 and the laser drive circuit 50 operate, and the pickup 40 emits thelight beam B in the recordable area 104 on the hybrid disc 1. At thistime, the power of the light beam B is changed over on the basis of themodulated signal Sre. Namely, when the recording information pit isformed on the groove track 2, the power of the light beam B is set atthe recording power, and when the recording information pit is notformed on the groove track 2, the power of the light beam B is set atthe reproducing power. That is, when the light beam B having therecording power is emitted onto the dye membrane 5, the reflectance ofthe dye membrane 5 is changed, and when the light beam B having thereproducing power is emitted onto the dye membrane 5, the reflectance ofthe dye membrane 5 is not changed. Thus, the information correspondingto the modulated signal Sre is recorded on the groove track 2 (Step 9).In addition, at this time, the pre-pits 4 and the wobbles of the groovetrack 2 are detected, the rotation of the hybrid disc 1 is controlled,the address information is fetched, and the recording of the informationis controlled by the processor 46.

On the other hand, at the step 7, if the processor 46 determines thatthe recording information is not recorded (Step 7; NO), the informationrecorded in the recordable area 104 or the reproducing informationrecorded in the ROM area 103 is reproduced. Namely, like thereproduction of the read-only disc, the switch 48 connects the constantvoltage to the power control circuit 49 on the basis of the switchingsignal Ssw, the pickup 40 emits the light beam B having the reproducingpower, and the processor 46 outputs the reproducing signal Sot on thebasis of the detected information from the recordable area 104 or theROM area 103.

As explained above, according to the hybrid disc 1, the cuttingapparatus 300 and the information recording/reproducing apparatus 500 ofthe embodiment of the present invention, the groove track 203 in the ROMarea 103 is constructed by the arrangement of the plurality of the dyepits P whose shapes correspond to the reproducing information, thereflectance of the light beam B is changed depending on presence orabsence of the dye pit P, the dye pits P and groove track 2 in therecordable track 104 are composed of the same dye material, and the dyepits P and the groove track 2 has the same height. Accordingly, when thehybrid disc 1 is produced, the groove track 202 (dye pits P) and thegroove track 2 are formed in the same process, and it is possible tosimplify the production process of the hybrid disc 1. That is, it ispossible to produce the hybrid disc 1 easy.

Furthermore, the groove track 202 is constructed by the arrangement ofthe dye pits P having shapes corresponding to the reproducinginformation. Accordingly, it is possible to reproduce the reproducinginformation surely.

Furthermore, the light beam B having the recording power is emitted ontothe all dye pits P in order to change the reflectance of the dye pits P,and thereafter, the reproducing information is reproduced by emittingthe light beam B having the reproducing power onto the dye pits whosereflectance have been changed. Accordingly, it is possible to reproducethe reproducing information surely.

Moreover, the characteristic of the dye pit P is changed by emitting thelight beam B having the recording power. Accordingly, it is possible tosimplify the configuration of the information recording/reproducingapparatus 500.

In addition, in the aforementioned embodiment, when reproduction orrecording is actually performed by the information recording/reproducingapparatus 500, the light beam B having the recording power is emittedonto the dye pits P in order to the reflection of the dye pits P.However, the present invention is not limit to this. For example, whenthe hybrid disc 1 is produced, the light beam B having the recordingpower may be emitted onto the dye pits P in order to the reflection ofthe dye pits P.

Furthermore, in the aforementioned embodiment, the light beam B havingthe recording power is emitted onto the dye pits P in order to thereflection of the dye pits P. However, the present invention is notlimited to this. For example, if changing the reflection of the dye pitsP is possible, the light beam B having a power weaker than the recordingpower may be emitted.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

What is claimed is:
 1. An information reproducing apparatus forreproducing information recorded on a dye record disc, the dye recorddisc comprising: a disc shape substrate having a track-forming-surfacedivided into a read-only area and a recordable area; a reproducing trackformed on the track-forming-surface in the read-only area, andconstructed by an arrangement of a plurality of pits, each of the pitscomprising a dye material, and having a shape corresponding to thereproducing information; and a recording/reproducing track formed on thetrack-forming-surface in the recordable area, and extendingcontinuously, the recording/reproducing track comprising the same dyematerial as each of the pits, the information reproducing apparatuscomprising: an initial light emitting device for emitting an initiallight beam to all of the pits before reproduction, in order to changereflectance of all of the pits; a reproducing light emitting device foremitting a reproducing light to each of the pits; a receiving device forreceiving a reflective light of the reproducing light reflected by thereproducing track, and generating a receiving signal corresponding tothe received reflective light; and a reproducing device for reproducingthe reproducing information on the basis of the receiving signal.
 2. Aninformation recording/reproducing apparatus for recording informationonto a dye record disc and reproducing information recorded on the dyerecord disc, the dye record disc comprising: a disc shape substratehaving a track-forming-surface divided into a read-only area arecordable area; a reproducing track formed on the track-forming-surfacein the read-only area, and constructed by an arrangement of a pluralityof pits, each of the pits comprising a dye material, and having a shapecorresponding to the reproducing information. recording/reproducingtrack formed on the track-forming-surface in the recordable area, andextending continuously, the recording/reproducing track comprising thesame dye material as each of the pits, the informationrecording/reproducing apparatus comprising: an initial light emittingdevice for emitting an initial light beam to all of the pits beforereproduction, in order to change reflectance of all of the pits; areproducing light emitting device for emitting a reproducing light toeach of the pits; a receiving device for receiving a reflective light ofthe reproducing light reflected by the reproducing track, and generatinga receiving signal corresponding to the received reflective light; areproducing device for reproducing the reproducing information on thebasis of the receiving signal; and a recording light emitting device foremitting a recording light modulated on the basis of the recordinginformation onto the recording/reproducing track, in order to record therecord information onto the recording/reproducing track by changingreflectance of the recording/reproducing track.
 3. An informationrecording/reproducing apparatus according to claim 2, wherein theinitial light emitting device emits the initial light beam having anintensity of the reproducing light.
 4. An information reproducing methodof reproducing information recorded on a dye record disc, the dye recorddisc comprising: a disc shape substrate having a track-forming-surfacedivided into a read-only area a recordable area; a reproducing trackformed on the track-forming-surface in the read-only area, andconstructed by an arrangement of a plurality of pits, each of the pitscomprising a dye material, and having a shape corresponding to thereproducing information; and a recording/reproducing track formed on thetrack-forming-surface in the recordable area, and extendingcontinuously, the recording/reproducing track comprising the same dyematerial as each of the pits, the information reproducing methodcomprising the process of: emitting an initial light beam to all of thepits before reproduction, in order to change reflectance of all of thepits; emitting a reproducing light to each of the pits; receiving areflective light of the reproducing light reflected by the reproducingtrack, and generating a receiving signal corresponding to the receivedreflective light; and reproducing the reproducing information on thebasis of the receiving signal.
 5. An information reproducing apparatusaccording to claim 1, wherein the initial light emitting device emitsthe initial light beam having an intensity of the reproducing light. 6.An information reproducing apparatus for reproducing informationrecorded on a read-only disc having a read-only area or reproducinginformation recorded on a dye record disc, the dye record disccomprising: a disc shape substrate having a track-forming-surfacedivided into the read-only area and a recordable area; a reproducingtrack formed on the track-forming-surface in the read-only area, andconstructed by an arrangement of a plurality of pits, each of the pitscomprising a dye material, and having a shape corresponding to thereproducing information; and a recording/reproducing track formed on thetrack-forming-surface in the recordable area, and extendingcontinuously, the recording/reproducing track comprising the same dyematerial as each of the pits, the information reproducing apparatuscomprising: a determining device for determining whether a disc mountedon the information reproducing apparatus is the dye record disc; aninitial light emitting device for emitting an initial light beam to theread-only area if the mounted disc is the dye record disc, in order tochange reflectance of all of the pits.
 7. An information reproducingapparatus according to claim 6, wherein the determining devicedetermines whether the mounted disc is the dye record disc on the basisof the TOC information of the mounted disc.
 8. An informationreproducing apparatus according to claim 6, wherein the initial lightemitting device emits the initial light beam having an intensity of thereproducing light.
 9. An information recording/reproducing apparatus forrecording information onto a dye record disc, and for reproducinginformation recorded on the dye record disc or on a read-only dischaving a read-only area, the dye record disc comprising: a disc shapesubstrate having a track-forming-surface divided into a read-only areaand a recordable area; a reproducing track formed on thetrack-forming-surface in the read-only area, and constructed by anarrangement of a plurality of pits, each of the pits comprising a dyematerial, and having a shape corresponding to the reproducinginformation; and a recording/reproducing track formed on thetrack-forming-surface in the recordable area, and extendingcontinuously, the recording/reproducing track comprising the same dyematerial as each of the pits, the information recording/reproducingapparatus comprising: a determining device for determining whether adisc mounted on the information reproducing apparatus is the dye recorddisc; an initial light emitting device for emitting an initial lightbeam to the read-only area if the mounted disc is the dye record disc,in order to change reflectance of all of the pits.
 10. An informationrecording/reproducing apparatus according to claim 9, wherein thedetermining device determines whether the mounted disc is the dye recorddisc on the basis of the TOC information of the mounted disc.
 11. Aninformation recording/reproducing apparatus according to claim 9,wherein the initial light emitting device emits the initial light beamhaving an intensity, the intensity being lower than that of thereproducing light and higher than that of the reproducing light.
 12. Aninformation recording/reproducing method of reproducing information on aread-only disc having a read-only area or reproducing informationrecorded on a dye record disc, the dye record disc comprising: a discshape substrate having a track-forming-surface divided into theread-only area a recordable area; a reproducing track formed on thetrack-forming-surface in the read-only area, and constructed by anarrangement of a plurality of pits; each of the pits comprising a dyematerial, and having a shape corresponding to the reproducinginformation; and a recording/reproducing track formed on thetrack-forming-surface in the recordable area, and extendingcontinuously, the recording/reproducing track comprising the same dyematerial as each of the pits, the information recording/reproducingmethod comprising the processes of: determining whether a disc mountedon the information reproducing apparatus is the dye record disc;emitting an initial light beam to the read-only area if the mounted discis the dye record disc, in order to change reflectance of all of thepits.